Are you a boy whose name ends in "n"? Congratulations, you are contributing to one of the weirdest naming trends in American history.

The rise in popularity of boys' names that end in "n" has been unprecedented. In 2009, baby name expert Laura Wattenberg told the New York Timesthat "n" has managed to achieve terminal-letter-ascendancy in a matter of decades, "[taking] over in a way that no ending has taken over before, for boys."

Crazy, right? At the time of her 2009 NYT interview, Wattenberg called the rise of the terminal-n "historically bizarre." It's only gotten weirder. Since 2011, four of the 10 most popular names for baby boys have ended in "n." A full 36% of boys' names now end in the letter.

An interesting example highlights the "n" craze from a few different angles: In 2008, when "Jayden" became the most popular name for newborn boys in New York City, many considered it a surprising frontrunner; second through fifth places, after all, had gone to the generally timeless, biblical boys' names of Daniel, Michael, Matthew and David. But to those in the know, the popularity of "Jayden" was less surprising. At the time, roughly one-in-three newborn American boys could be expected to leave the hospital with a name ending in "n." In New York City, specifically, the name had been on an upswing within minority populations for years, ranking tenth, city-wide, in 2006 and second in 2007. Moreover, "Jayden" reached peak popularity in a year when forty of the top 1,000 names for newborn American boys rhymed with "Aiden." Names like Braden, Hayden, Kaden, Raiden, Zaiden and, yes, Jayden.

The existence of an extensive "Aiden" rhyming family (and closely related lineages, like the Payton-Clayton-Dayton-Layton-Trayton clan) is fascinating in its own right. For one thing, it helps explain the ends-in-n phenomenon. When you consider that each of these names can be spelled any number of ways (Jaden, Jadon, Jadyn, Jaeden, Jaiden, Jaidyn, Jaydan, Jaydin and Jaydon all being common variants of Jayden, for instance), the meteoric rise of the nominally terminal "n" makes a lot more sense.

But then why does this rhyming family exist in the first place? Where does it come from? Personally, I like Wattenberg's hypothesis, which she puts forth in a recent blog entry at Baby Name Wizard. In a nutshell, she argues that what's changed isn't how we name, but how we spell. "Replacing John with Aiden, Aidan, Ayden, Aidyn, Aden, Aydin and Ayden could make for a statistical fracturing of popularity without any greater variety in spoken names," she explains. In other words: The names may appear different on the page, but they still sound identical to your ear.

In fact, Wattenberg finds that if you treat everything in the "Aiden" rhyming family ("from Aaden to Zayden") as one mega-name, the group's popularity actually approaches that of perennial favorites like "Robert." "Put it all together," Wattenberg writes, "and the defining characteristic of this naming era is parents' desire to feel that their child's name is distinctive."

What's fascinating is that parents seem to measure a name's distinctiveness not by its sound, but by its spelling. The delightful irony, of course, is that in seeking to diversify the way we spell our children's names, we wind up converging on a surprisingly homogenized sound. The more names change, the more they stay the same.

Many thanks to David Taylor for allowing us to use his visualizations for this post. If you're into datavisualization, we highly recommend checking out his (enormous time-suck of a) blog, prooffreader.